Method For Evaluating Birefringence Of Adhesive, Method For Designing Adhesive, Method For Producing Adhesive, Adhesive, Polarizing Plate, Liquid Crystal Display Device, Method For Producing Polarizing Plate And Method For Producing Liquid Crystal Display Device

Abstract

Methods of evaluating birefringence of an adhesive agent, and of designing and producing an adhesive agent using the evaluation method, as well as adhesive agents produced using these methods. A polarizing plate and a liquid crystal display device using the obtained adhesive agent are proposed, as well as methods for producing the same.

1 . A method of evaluating birefringence of an adhesive agent comprising:
 preparing a laminated film by applying an adhesive agent to a support body which comprises a polymer film whose inherent birefringence is 1×10 −3  or less;   heat-drawing said laminated film; and   measuring retardation of the laminated film after being heat-drawn and the layer-thickness of said adhesive agent.   
     
     
         2 . The method of evaluating birefringence according to  claim 1 , wherein for said polymer film, the photoelastic coefficient thereof is 1×10 −12  Pa −1  or less by the absolute value. 
     
     
         3 . The method of evaluating birefringence according to  claim 1 , wherein said laminated film is a laminated film formed by sandwiching said adhesive agent between said two sheets of support bodies. 
     
     
         4 . The method of evaluating birefringence according to a  claim 1 , wherein said heat-drawing is carried out under a glass-transition temperature or more of said polymer film. 
     
     
         5 . The method of evaluating birefringence according to  claim 1 , wherein said heat-drawing is carried out under a condition of 70° C. to 150° C. drawing temperature, 50%/min to 1000%/min drawing speed and draw ratio of 1.1 times to 3 times. 
     
     
         6 . A method of designing an adhesive agent comprising:
 measuring birefringences of plural kinds of adhesive polymer compositions which include polymers and which are used for samples by for each adhesive polymer composition, preparing a laminated film by applying the adhesive agent to a support body which comprises a polymer film whose inherent birefringence is 1×10 −3  or less, heat-drawing said laminated film, and measuring retardation of the laminated film after being heat-drawn and the layer-thickness of said adhesive agent;   calculating birefringence corresponding to each repeating unit in said polymers from the values of said birefringences of said polymer compositions,   determining the combination and the combination ratio of the repeating units and for determining the polymer structure based on said obtained birefringence value for every of the repeating units, and   applying said determined polymer to the adhesive agent.   
     
     
         7 . The method of designing an adhesive agent according to  claim 6 , wherein a repeating unit in which said birefringence value indicates a negative value and a repeating unit in which said birefringence value indicates a positive value are combined in the process for determining the combination and the combination ratio of said repeating units and for determining the polymer structure. 
     
     
         8 . The method of designing an adhesive agent according to  claim 6  further comprising adjusting the birefringence value by compounding an addition agent or a curative agent. 
     
     
         9 . The method of designing an adhesive agent according to  claim 6 , wherein
 in case of applying a polymer, whose gel fraction expressed by
   [gel fraction(%)]=[mass of insoluble portion( g )]×100/[mass of adhesive agent( g )]
 
   
       is 0.1% or more and less than 80%, to the adhesive agent,
 heat-drawing in said birefringence evaluation method is carried out by drawing temperature of 102° C., by drawing speed of 400%/min and by draw ratio of twice, and the combination and the combination ratio of said repeating units are determined such that the absolute value of the birefringence obtained by adding, in response to the combination ratio, the birefringence value for every of said repeating units, which were obtained at that time, becomes 4×10 −4  or less, whereby the polymer structure is determined. 
 
     
     
         10 . The method of designing an adhesive agent according to  claim 6 , wherein
 in case of applying a polymer, whose gel fraction expressed by
   [gel fraction(%)]=[mass of insoluble portion( g )]×100/[mass of adhesive agent( g )]
 
   
       is 80% or more, to the adhesive agent,
 heat-drawing in said birefringence evaluation method is carried out by drawing temperature of 102° C., by drawing speed of 400%/min and by draw ratio of twice, and the combination and the combination ratio of said repeating units are determined such that the absolute value of the birefringence obtained by adding, in response to the combination ratio, the birefringence value for every of said repeating units, which were obtained at that time, becomes 15×10 −4  or less, whereby the polymer structure is determined. 
 
     
     
         11 . A method of producing an adhesive agent comprising:
 measuring birefringences of plural kinds of adhesive polymer compositions which include polymers and which are used for samples by, for each adhesive polymer composition, preparing a laminated film by applying the adhesive agent to a support body which comprises a polymer film whose inherent birefringence is 1×10 −3  or less, heat-drawing said laminated film, and measuring retardation of the laminated film after being heat-drawn and the layer-thickness of said adhesive agent;   calculating birefringence corresponding to each repeating unit in said polymers from the values of said birefringences of said polymer compositions,   determining the combination and the combination ratio of the repeating units based on said obtained birefringence value for every of the repeating units,   synthesizing a polymer by polymerizing monomers corresponding to said repeating units by said determined ratio, and   applying said synthesized polymer to the adhesive agent.   
     
     
         12 . The method of producing an adhesive agent according to  claim 11 , wherein a repeating unit in which said birefringence value indicates a negative value and a repeating unit in which said birefringence value indicates a positive value are combined in the process for determining the combination and the combination ratio of said repeating units. 
     
     
         13 . The method of producing an adhesive agent according to  claim 11  further comprising adjusting the birefringence value by compounding an addition agent or a curative agent. 
     
     
         14 . An adhesive agent produced by a method comprising:
 measuring birefringences of plural kinds of adhesive polymer compositions which include polymers and which are used for samples by for each adhesive polymer composition, preparing a laminated film by applying the adhesive agent to a support body which comprises a polymer film whose inherent birefringence is 1×10 −3  or less, heat-drawing said laminated film, and measuring retardation of the laminated film after being heat-drawn and the layer-thickness of said adhesive agent;   calculating birefringence corresponding to each repeating unit in said polymers from the values of said birefringences of said polymer compositions,   determining the combination and the combination ratio of the repeating units based on said obtained birefringence value for every of the repeating units,   synthesizing a polymer by polymerizing monomers corresponding to said repeating units by said determined ratio, and   applying said synthesized polymer to the adhesive agent.   
     
     
         15 . An adhesive agent produced by a method comprising:
 measuring birefringences of plural kinds of adhesive polymer compositions which include polymers and which are used for samples by, for each adhesive polymer composition,   preparing a laminated film by applying the adhesive agent to a support body which comprises a polymer film whose inherent birefringence is 1×10 −3  or less, heat-drawing said laminated film, and measuring retardation of the laminated film after being heat-drawn and the layer-thickness of said adhesive agent;   calculating birefringence corresponding to each repeating unit in said polymers from the values of said birefringences of said polymer compositions,   determining the combination and the combination ratio of the repeating units based on said obtained birefringence value for every of the repeating units,   synthesizing a polymer by polymerizing monomers corresponding to said repeating units by said determined ratio, and   applying said synthesized polymer to the adhesive agent;   wherein a repeating unit in which said birefringence value indicates a negative value and a repeating unit in which said birefringence value indicates a positive value are combined in the step of determining the combination and the combination ratio of said repeating units.   
     
     
         16 . The adhesive agent of  claim 15  wherein the method further comprises adjusting the birefringence value by compounding an addition agent or a curative agent. 
     
     
         17 . The method of  claim 11 , wherein
 in case of applying a polymer, whose gel fraction expressed by
   [gel fraction(%)]=[mass of insoluble portion( g )]×100/[mass of adhesive agent( g )]
 
   
       is 0.1% or more and less than 80%, to the adhesive agent,
 heat-drawing in said birefringence evaluation method is carried out by drawing temperature of 102° C., by drawing speed of 400%/min and by draw ratio of twice, and the combination and the combination ratio of said repeating units are determined such that the absolute value of the birefringence obtained by adding, in response to the combination ratio, the birefringence value for every of said repeating units, which were obtained at that time, becomes 4×10 −4  or less. 
 
     
     
         18 . The method of  claim 11 , wherein
 in case of applying a polymer, whose gel fraction expressed by
   [gel fraction(%)]=[mass of insoluble portion( g )]×100/[mass of adhesive agent( g )]
 
   
       is 0.1% or more and less than 80%, to the adhesive agent,
 said heat-drawing is carried out by drawing temperature of 102° C., by drawing speed of 400%/min and by draw ratio of twice, and the combination and the combination ratio of said repeating units are determined such that the absolute value of the birefringence obtained by adding, in response to the combination ratio, the birefringence value for every of said repeating units, which were obtained at that time, becomes 15×10 −4  or less. 
 
     
     
         19 . An adhesive agent obtained by
 measuring birefringences of plural kinds of adhesive polymer compositions which include polymers and which are used for samples by, for each adhesive polymer composition, preparing a laminated film by applying the adhesive agent to a support body which comprises a polymer film whose inherent birefringence is 1×10 −3  or less, heat-drawing said laminated film, and measuring retardation of the laminated film after being heat-drawn and the layer-thickness of said adhesive agent;   calculating birefringence corresponding to each repeating unit in said polymers from the values of said birefringences of said polymer compositions,   determining the combination and the combination ratio of the repeating units based on said obtained birefringence value for every of the repeating units,   synthesizing a polymer by polymerizing monomers corresponding to said repeating units by said determined ratio, and   
       applying said synthesized polymer to the adhesive agent; 
       wherein the absolute value of the birefringence obtained when carrying out the heat-drawing by drawing temperature of 102° C., by drawing speed of 400%/min and by draw ratio of twice is 4×10 −4  or less, and the gel fraction is 0.1% or more and less than 80%. 
     
     
         20 . An adhesive agent obtained by
 measuring birefringences of plural kinds of adhesive polymer compositions which include polymers and which are used for samples by, for each adhesive polymer composition, preparing a laminated film by applying the adhesive agent to a support body which comprises a polymer film whose inherent birefringence is 1×10 −3  or less, heat-drawing said laminated film, and measuring retardation of the laminated film after being heat-drawn and the layer-thickness of said adhesive agent;   calculating birefringence corresponding to each repeating unit in said polymers from the values of said birefringences of said polymer compositions,   determining the combination and the combination ratio of the repeating units based on said obtained birefringence value for every of the repeating units,   synthesizing a polymer by polymerizing monomers corresponding to said repeating units by said determined ratio, and   
       applying said synthesized polymer to the adhesive agent; 
       wherein the absolute value of the birefringence obtained when carrying out the heat-drawing by drawing temperature of 102° C., by drawing speed of 400%/min and by draw ratio of twice is 15×10 −4  or less, and the gel fraction is 80% or more. 
     
     
         21 . A method of producing a polarizing plate comprising bonding a polarizing film and a glass substrate together by using an adhesive agent obtained by the method according to  claim 11 . 
     
     
         22 . A method of producing a liquid crystal display device including a backlight, a liquid crystal layer, and a polarizing plate having a polarizing film and a glass substrate, comprising a process for bonding said polarizing film and said glass substrate together by using an adhesive agent obtained by the method according to  claim 11 . 
     
     
         23 . A polarizing plate, comprising a polarizing film and a glass substrate that are bonded together by an adhesive agent obtained by
 measuring birefringences of plural kinds of adhesive polymer compositions which include polymers and which are used for samples by, for each adhesive polymer composition, preparing a laminated film by applying the adhesive agent to a support body which comprises a polymer film whose inherent birefringence is 1×10 −3  or less, heat-drawing said laminated film, and measuring retardation of the laminated film after being heat-drawn and the layer-thickness of said adhesive agent;   calculating birefringence corresponding to each repeating unit in said polymers from the values of said birefringences of said polymer compositions,   determining the combination and the combination ratio of the repeating units based on said obtained birefringence value for every of the repeating units,   synthesizing a polymer by polymerizing monomers corresponding to said repeating units by said determined ratio, and   applying said synthesized polymer to the adhesive agent;   wherein the absolute value of the birefringence obtained when carrying out the heat-drawing by drawing temperature of 102° C., by drawing speed of 400%/min and by draw ratio of twice is 4×10 −4  or less, and the gel fraction is 0.1% or more and less than 80%.   
     
     
         24 . A liquid crystal display device comprising a backlight, a liquid crystal layer, a polarizing plate having a polarizing film and a glass substrate, wherein said polarizing film and said glass substrate are bonded together by an adhesive agent obtained by
 measuring birefringences of plural kinds of adhesive polymer compositions which include polymers and which are used for samples by, for each adhesive polymer composition, preparing a laminated film by applying the adhesive agent to a support body which comprises a polymer film whose inherent birefringence is 1×10 −3  or less, heat-drawing said laminated film, and measuring retardation of the laminated film after being heat-drawn and the layer-thickness of said adhesive agent;   calculating birefringence corresponding to each repeating unit in said polymers from the values of said birefringences of said polymer compositions.   determining the combination and the combination ratio of the repeating units based on said obtained birefringence value for every of the repeating units,   synthesizing a polymer by polymerizing monomers corresponding to said repeating units by said determined ratio, and   applying said synthesized polymer to the adhesive agent;   wherein the absolute value of the birefringence obtained when carrying out the heat-drawing by drawing temperature of 102° C., by drawing speed of 400%/min and by draw ratio of twice is 4×10 −4  or less, and the gel fraction is 0.1% or more and less than 80%.   
     
     
         25 . An adhesive agent, wherein the absolute value of the adhesive's inherent birefringence which is obtained by the method of  claim 5  is 4×10 −4  or less. 
     
     
         26 . An adhesive agent, wherein the absolute value of the adhesive's inherent birefringence which is obtained by the method of  claim 5  is 2×10 −4  or less. 
     
     
         27 . An adhesive agent, wherein the absolute value of the adhesive's inherent birefringence which is obtained by the method of  claim 9  is 4×10 −4  or less. 
     
     
         28 . An adhesive agent, wherein the absolute value of the adhesive's inherent birefringence which is obtained by the method of  claim 9  is 2×10 −4  or less. 
     
     
         29 . A polarizing plate comprising an adhesive agent according to  claim 25 . 
     
     
         30 . An adhesive agent obtained by the method of  claim 10  in which the gel fraction is 80% or more and the absolute value of the adhesive's inherent birefringence is 15×10 −4  or less. 
     
     
         31 . The adhesive agent according to  claim 30 , wherein the gel fraction thereof is 85% or more. 
     
     
         32 . A method of evaluating birefringence of an adhesive agent comprising:
 drawing the adhesive agent which lies on a polymer film together with the polymer film and for forming a drawn film;   measuring retardation of said drawn film; and   measuring layer-thickness of said adhesive agent, wherein   the birefringence is found by dividing said retardation by said thickness.   
     
     
         33 . A method of evaluating birefringence of an adhesive agent comprising:
 drawing a sample obtained by sandwiching the adhesive agent between two sheets of polymer films;   measuring retardation inside the film surface of said polymer film; and,   measuring layer-thickness of said adhesive agent; wherein   the birefringence is found by dividing said retardation by said thickness.   
     
     
         34 . A polarizing plate, comprising at least one film selected from the group consisting of a polarizing-plate protection film in which the absolute value of the photoelastic coefficient is 8×10 −12  Pa −1  or less, or a phase-difference film in which the absolute value of the photoelastic coefficient is 8×10 −12  Pa −1  or less,
 and wherein the polarizing plate is bonded with an adhesive agent produced by a method comprising: 
 measuring birefringences of plural kinds of adhesive polymer compositions which include polymers and which are used for samples by, for each adhesive polymer composition, 
 preparing a laminated film by applying the adhesive agent to a support body which comprises a polymer film whose inherent birefringence is 1×10 −3  or less, heat-drawing said laminated film, and measuring retardation of the laminated film after being heat-drawn and the layer-thickness of said adhesive agent; 
 calculating birefringence corresponding to each repeating unit in said polymers from the values of said birefringences of said polymer compositions, 
 determining the combination and the combination ratio of the repeating units based on said obtained birefringence value for every of the repeating units, 
 synthesizing a polymer by polymerizing monomers corresponding to said repeating units by said determined ratio, and 
 applying said synthesized polymer to the adhesive agent; 
 wherein a repeating unit in which said birefringence value indicates a negative value and a repeating unit in which said birefringence value indicates a positive value are combined in the step of determining the combination and the combination ratio of said repeating units; and, 
 wherein the birefringence value is adjusted by compounding an addition agent or a curative agent. 
 
     
     
         35 . A method of designing an adhesive agent comprising:
 obtaining the birefringence value of an adhesive polymer composition including at least one of an addition agent and a curative agent, and a polymer by preparing a laminated film by applying the adhesive agent to a support body which comprises a polymer film whose inherent birefringence is 1×10 −3  or less, heat-drawing said laminated film, and measuring retardation of the laminated film after being heat-drawn and the layer-thickness of said adhesive agent; and   determining the ratio between the polymer and the compound material based on the birefringence value of said polymer composition and for applying it to the adhesive agent.   
     
     
         36 . A method of producing an adhesive agent comprising:
 obtaining the birefringence value of an adhesive polymer composition including at least one of an addition agent and a curative agent, and a polymer by preparing a laminated film by applying the adhesive agent to a support body which comprises a polymer film whose inherent birefringence is 1×10 −3  or less, heat-drawing said laminated film, and measuring retardation of the laminated film after being heat-drawn and the layer-thickness of said adhesive agent; and   determining the ratio between the polymer and the compound material based on the birefringence value of said polymer composition and for applying it to the adhesive agent.   
     
     
         37 . An adhesive agent produced by:
 obtaining the birefringence value of an adhesive polymer composition including at least one of an addition agent and a curative agent, and a polymer by preparing a laminated film by applying the adhesive agent to a support body which comprises a polymer film whose inherent birefringence is 1×10 −3  or less, heat-drawing said laminated film, and measuring retardation of the laminated film after being heat-drawn and the layer-thickness of said adhesive agent; and   determining the ratio between the polymer and the compound material based on the birefringence value of said polymer composition and for applying it to the adhesive agent.   
     
     
         38 . The method of  claim 8 , wherein said addition agent is a compound including at least two pieces of aromatic rings inside the molecule. 
     
     
         39 . The method of  claim 13 , wherein said addition agent is a compound including at least two pieces of aromatic rings inside the molecule. 
     
     
         40 . The adhesive agent according to  claim 37 , wherein said addition agent is a compound including at least two pieces of aromatic rings inside the molecule. 
     
     
         41 . An adhesive agent, wherein the absolute value of the adhesive's inherent birefringence which is obtained by the method of evaluating birefringence according to  claim 5  is 15×10 −4  or less and the gel fraction is 80% or more. 
     
     
         42 . The method of  claim 35 , wherein said addition agent is a compound including at least two pieces of aromatic rings inside the molecule. 
     
     
         43 . The method of  claim 36 , wherein said addition agent is a compound including at least two pieces of aromatic rings inside the molecule. 
     
     
         44 . A method of producing an adhesive agent comprising:
 measuring birefringences of plural kinds of adhesive polymer compositions which include polymers and which are used for samples by, for each adhesive polymer composition,   preparing a laminated film by applying the adhesive agent to a support body which comprises a polymer film whose inherent birefringence is 1×10 −3  or less, heat-drawing said laminated film, and measuring retardation of the laminated film after being heat-drawn and the layer-thickness of said adhesive agent;   calculating birefringence corresponding to each repeating unit in said polymers from the values of said birefringences of said polymer compositions,   determining the combination and the combination ratio of the repeating units based on said obtained birefringence value for every of the repeating units,   synthesizing a polymer by polymerizing monomers corresponding to said repeating units by said determined ratio, and   applying said synthesized polymer to the adhesive agent;   wherein a repeating unit in which said birefringence value indicates a negative value and a repeating unit in which said birefringence value indicates a positive value are combined in the step of determining the combination and the combination ratio of said repeating units;   wherein the birefringence value is adjusted by compounding an addition agent or a curative agent; and,   wherein said addition agent is a compound including at least two pieces of aromatic rings inside the molecule.   
     
     
         45 . A polarizing plate, comprising a polarizing film and a glass substrate that are bonded together by An adhesive agent obtained by
 measuring birefringences of plural kinds of adhesive polymer compositions which include polymers and which are used for samples by, for each adhesive polymer composition, preparing a laminated film by applying the adhesive agent to a support body which comprises a polymer film whose inherent birefringence is 1×10 −3  or less, heat-drawing said laminated film, and measuring retardation of the laminated film after being heat-drawn and the layer-thickness of said adhesive agent;   calculating birefringence corresponding to each repeating unit in said polymers from the values of said birefringences of said polymer compositions,   determining the combination and the combination ratio of the repeating units based on said obtained birefringence value for every of the repeating units,   synthesizing a polymer by polymerizing monomers corresponding to said repeating units by said determined ratio, and   applying said synthesized polymer to the adhesive agent;   wherein the absolute value of the birefringence obtained when carrying out the heat-drawing by drawing temperature of 102° C., by drawing speed of 400%/min and by draw ratio of twice is 15×10 −4  or less, and the gel fraction is 80% or more.   
     
     
         46 . A liquid crystal display device comprising a backlight, a liquid crystal layer, a polarizing plate having a polarizing film and a glass substrate, wherein said polarizing film and said glass substrate are bonded together an adhesive agent obtained by
 measuring birefringences of plural kinds of adhesive polymer compositions which include polymers and which are used for samples by, for each adhesive polymer composition, preparing a laminated film by applying the adhesive agent to a support body which comprises a polymer film whose inherent birefringence is 1×10 −3  or less, heat-drawing said laminated film, and measuring retardation of the laminated film after being heat-drawn and the layer-thickness of said adhesive agent;   calculating birefringence corresponding to each repeating unit in said polymers from the values of said birefringences of said polymer compositions,   determining the combination and the combination ratio of the repeating units based on said obtained birefringence value for every of the repeating units,   synthesizing a polymer by polymerizing monomers corresponding to said repeating units by said determined ratio, and   applying said synthesized polymer to the adhesive agent;   wherein the absolute value of the birefringence obtained when carrying out the heat-drawing by drawing temperature of 102° C., by drawing speed of 400%/min and by draw ratio of twice is 15×10 −4  or less, and the gel fraction is 80% or more.